NEW YORK — Frits van Paasschen, the energetic CEO of Starwood Hotels & Resorts Worldwide Inc., resigned Tuesday morning. No reason was given for the sudden departure, but the company said it was “by mutual agreement” with the board of directors.

Chairman of the Board Bruce W. Duncan told investors on a call Tuesday morning that “now is the right time to turn to new leadership.” He said there was no disagreement over strategy but the move was made to better execute that growth plan.

The Stamford-based hotel company has been led by van Paasschen since September 2007. Last week, Starwood announced plans to spin off its timeshare business as a separate company, but Duncan said that was unrelated.

Shares of Starwood shot up 4 percent at the stock market’s open.

The operator of Westin, Sheraton, W, St. Regis and other hotel brands says board member Adam Aron, 60, will serve as interim CEO until a permanent replacement is found. Aron has been on Starwood’s board since 2006. He is the former CEO of both Vail Resorts and Norwegian Cruise Line. He also served as CEO of the Philadelphia 76ers from 2011 through 2013. Aron has been CEO of leisure-related consultancy World Leisure Partners Inc. since 2006.

Aron told investors Tuesday that Starwood can improve its revenue and speed up the number of hotels it has under development.

“We can do better,” he said on the call.

Starwood is known for its strength in luxury hotels like St. Regis and lifestyle brands such as W. It, however, lacks a large number of limited-service properties — hotels like Holiday Inn Express and Marriott’s Fairfield Inn that offer a room but lack restaurants and room service. Aron said the leadership is “mindful of this as we look ahead.”

Van Paasschen, 53, will remain with Starwood as a consultant to help with the transition.

During his tenure, van Paasschen pushed his executives to better understand the cultures in which they are opening hotels. He moved the company’s entire leadership team to China for a month in 2011 and to the United Araba Emirates for a month in 2013. The group was scheduled to head to India this spring, a trip that is now being re-evaluated.

A vegan and triathlete, van Paasschen injected parts of his lifestyle into Starwood’s hotels. He’s changed menus to make them healthier, for instance, and made it easier for road warriors to work out.

Before arriving at Starwood, van Paasschen was CEO of Coors Brewing Co. and before that, he held several positions with Nike, ultimately overseeing its business in Europe, the Middle East and Africa. He was previously a vice president in finance at Disney Consumer Products and began his career as a consultant at the Boston Consulting Group and McKinsey & Co.

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AP Business Writer Michelle Chapman contributed to this report from West Orange, N.J.